Chroma Keying, DV and 4:2:2

mjroddy wrote on 6/27/2005, 3:07 PM
I know I'm slow, but I STILL don't get 4:2:2 in DV.
I own Gear Shift, Vegas 6 and a Sony Z1u.
This is how dopy I am: it seems to me that if I encode chroma keyed footage in using, say, Cineform's AspectHD, I have your basic HD footage (that's not MPEG2). So the footage is a little compromised already. Now I Gearshift it to 4:2:2 to take advantage of the colorspace for chromakeying. Aren't I still keying DV footage: Like, if I take a picture of a black and white poster, even though my color space on my digital camera is much greater, I'm still only using what I started with.
So then I think, encode the raw MPG2 file stream and Shifting that to 4:2:2. But I'm still DV, right?
My last thought was to take the footage in via component (which I can't do with the equipment I presently own), and that could be encoded 4:2:2, but I'm getting lost.
Can some Master help a vaguely technologlically challenged individual with this whold thought process? I'm hoping I won't be the only one to benefit.
Thank you.

Comments

Marco. wrote on 6/27/2005, 3:21 PM
This maybe ain't not really help but ...

... have you ever tried what great keying results you can get with Vegas even if you use 4:2.0 DV (I think 4:1:1 DV should be very similar if not same)?

I dayly work with rather expensiv SDI 4:2:2 hardware keying equipment in live surroundings. But I also know about the keying power of Vegas.

Just use the Chroma Blur filter first to get rid of some rough DV edges and choose one of the two chroma keyers (yes - there are two indeed: sometimes it's a better choice to use the Color Corrector Secondary for chroma keying, e.g. for cascading the key). Sometimes some color tweeking using Color Curves can help but most of the time only Chroma Blur and one of the two Chroma Keyers gives me perfect results.
I never had the need to ask for 4:2:2 footage for Vegas keying.

Marco
vitalforce2 wrote on 6/27/2005, 4:25 PM
$.02 worth: I've had good results using just the Secondary Color Corrector to (1) turn green grass brown, and (2) turn a large swath of green grass into recent snowfall.
mjroddy wrote on 6/27/2005, 4:45 PM
Yes.
For DV footage, my usual workflow is
Secondary Color Corrector boosting the greens.
Chroma Blur
Chroma Key
Now... I know it isn't fair to compair, but I'm really spoiled on my Beta SP background of chroma keying. I'm hoping with HDV and 4:2:2, I can get comparable results.
At HOME, I have Serious Magic (Thank again!!!), but here at WORK (my 9-6 job), I'm stuck with the basics.
I have a project coming up that will require chroma keying, so without experimenting (who has time!?) I'm trying to decide if I want to use my BetaSP with Speed Razor and Boris Red or our Sony Z1u and Vegas.
Thanks again!
ronnierokk wrote on 6/27/2005, 6:24 PM
I've found that Vegas does indeed work great for keying.

I use it alot and sometimes combind the keying power of Ultra with vegas.

I like the fact that Ultra gives you the abillity to crop out all four sides with out distorting the video, such as in Vegas you would have to move the video in, as in a zoom fashion to do this.

But it does work well for what I do.

farss wrote on 6/27/2005, 7:06 PM
10bit 4.2.2 (which HDV isn't) keys, CCs and composites way better than "DV" but it's rather expensive to deal with. As I just found out to handle SD 10bit 4.2.2 I'm needing 93GB/hour of material and I've got over 10 hours to ingest.
I'm thinking I'll ingest as DV25, edit and get client sign off and then recapture just what's needed at 4.2.2.
Trying to get this project to flyas I'd originally started out would mean tying up 2TB of expensive storage for way too long.
Spot|DSE wrote on 6/28/2005, 12:31 AM
while 10 bit keys substantially better than 8 bit, converting m2t to 4:2:2 in GearShift (or otherwise) or to CineForm will result in WONDERFUL keys in Vegas or Ultra, or Ultra 2.
My workflow on this tour has been:
Capture m2t file.
Convert immediately to 4:2:2 CineForm or YUV
Key. (you don't need ChromaBlur at all with the 4:2:2, but it's nice to have access to)
That's it. You can drop the 4:2:2 directly into a DV timeline, or HDV timeline regardless of what it is. Just be sure that if you render to a 4:2:2 YUV file that you keep the properties of the file so that the 1.333 aspect ratio of an HDV timeline don't mess you up.
mjroddy wrote on 6/28/2005, 9:01 AM
Thanks everyone.
And thanks Mr Spot for the work flow. That helps a lot.